Heteroatom-Bridged Calixarenes

Abstract

Macrocycles have always played an important role in supramolecular chemistry. Macrocycles with rigid subunits, known as calixarenes, are an important subclass of these compounds. While carbon‐bridged calixarenes have been studied intensively and are used for practical applications, heteroatom‐bridged calixarenes have entered the stage more recently. This review summarizes the current knowledge of synthesis and properties of heteroatom‐bridged calixarenes in the year 2000.

Synthesis, Structure, and [60]Fullerene Complexation Properties of Azacalix[m]arene[n]pyridines

“…The past decade has seen a tremendous development in calixarene chemistry, and it has now become an indispensable part of supramolecular chemistry 12–15. While efforts are still being expended on derivatization of basic calixarene skeletons to improve their cavities and therefore their selective recognition properties towards various guest molecules, a more recent development in this field is the construction of new calixarenes by replacing the methylene bridges with heteroatoms16 such as nitrogen,17 sulphur,18 and other elements,16, 19 or their phenol units with pyrrole,20 pyridine,21 and other heteroarene species 16. 22 This has led to a number of intriguing macrocycles, such as thiacalixarenes18 and calixpyrroles 20.…”

Conformations of calix[4]arenes — an investigation based on CSD data. Part I. Cone conformers of methylene- and heteroatom-bridged calix[4]arenes

“…Calix [4]arenes are a class of macrocyclic compounds which has recently attracted a lot of attention because of their possible utilization in many areas of research and industry. Because of their potential, the chemistry of calixarenes has in the last few years developed into a wide and well-explored area [1].…”

“…The utilization of calix [4]arenes as molecular platforms possesses a few advantages. First, the synthesis of these macrocycles can be easily accomplished by a well-known procedure in good yields.…”

“…The starting materials (p-tert.butylphenol and formaldehyde) are inexpensive and common. Calix [4]arenes can be easily modified both on their upper and lower rim [3], which allows their chemical and physical properties to change as required. Finally, the four possible conformations of the calix [4]arene macrocycle, easily immobilized by lower rim substitution [2], are the main reason for the advantage of using calix [4]arenes as molecular platforms.…”

Homooxacalixarenes: II. Receptor properties

“…The extremely high intensity of research in the field of calix[n]arene chemistry within the last two decades in all industrially developed countries suggests that an independent field of supramolecular chemistry came into exist- Most recently heterocalixarenes are extensively involved into studies [93]. The presence of a heteroatom instead of a CH 2 bridge affects the size of the calixarene cavity, the symmetry of the molecule, its receptor properties, and becomes an additional recognition center.…”